Interlocking control apparatus



July 25, 41939.

Ac; H. LAY

INTERLOCKING CONTROL APPARATUS Filed Dec. 5, 1938 R Y NN m m Q mL R n vm HRH M NQ MJMPNNQ mvrNN MM S w 1 p .1 vlm @l @mgm ,m m H NEA C si .wk.u MN L Q w 1N@ .JI wvm u@ @Jim wm AFM@ M ma, www Y @5mm m. im H AN im,wm www vw l I w@ Patented July 25, 1939 UNITED STATES ammi PATENT OFFCECharles H. Lay, Swissvale, Pa., assignor to The Union Switch & SignalCompany, Swissvale,

Pa., a corporation of Pennsylvania Application December 3, 1938, SerialNo. 243,874

6 Claims.

My invention relates to interlocking control apparatus for railway trackswitches and signals in railway switching or interlocking layouts.

One feature of my invention is the provision of novel and impro-vedmeans for protection against unsafe conditions which might exist when aninterlocking system, which is provided with only one source of power, isagain supplied with power from that source after a power interruption.Another feature oi my invention is the provision of means for reducingtrain delays iollowing restoration, of power from the single source.

I shall describe one form of apparatus embodying my invention, and shallthen point out the novel features thereof in claims.

The accompanying drawing is a diagrammatic View showing one form ofapparatus embodying my invention.

Referring to the drawing, a portion of a railway interlocking layout isshown comprising two tracks interconnected by means of a crossover withswitches 3 and 3a. The lower one oi the two tracks, as shown in thedrawing, is divided by means oi insulated joints 5 in rails I and la toform two track sections comprising an approach section designated by thereference character ZRAT, and a detector section designated by thereference character 2T. The upper track, as shown in the drawing, issimilarly divided by insulated joints 6 in rails 5 and 5a to form anapproach section liLAT and a detector section 4T.

Each track section is provided with a track circuit including a sourceof current, shown as the secondary winding of a transformer l connectedacross the rails adjacent one end of the section, and the track winding8 of a two-element track relay, designated by the reference character Ror SR with a distinguishing prefix comprising the reference characterfor the associated track section, connected across the rails adjacentthe other end oi the section. Each of the track relays, as shown, isalso provided with a local element 9. The local element 9 of each of thedetector section track relays ZTSR and TSR is provided with two pick-upcircuits and a stick circuit.

A power-off stick relay, designated by the reierence character POSR, hasa pick-up circuit including a front contact of each of the relays ZTSRand QTSR. The power-ofi relay has also a stick circuit controlled byonly a front contact of the power-off relay.

Assuming that, as shown in the drawing, the direction from the left-handend of the interlocking layout toward the right-hand end is eastbound, asignal 2R is shown adjacent the entrance end of section 2T for governingeastbound traic movements into this section. A similar signal 4L islshown adjacent the entrance end of section 4T for governing westboundtrafc movements into section 4T. Each of these signals, as shown in thedrawing, is of the color light type comprising a yellow lamp Y, fordirecting traino movements into the corresponding track section, and ared lamp R indicating stop.

Each of the signals 2R and L is controlled by a signal relay designatedby the reference character HR with a pre1-lx corresponding to thereierence character for its signal. Each signal relay I-lR is controlledby a contact of the track relay for the detector section into which itssignal directs tranic movements, and by a reverse contact of a manuallyoperable signal lever designated by the reference character V with apreiiX corresponding to the number in the reference character for theassociated signal.

As shown in the drawing, each of the signal levers 2V and 4V has acenter or normal position N, a reverse position L to the left which canbe used for controlling a westbound signal, a normal lock or indicationposition B to the leit, a reverse position R to the right, and a normallock or indication position D to the right. In the drawing, however,each of the levers ZV and 4V is shown controlling'a signal for only onedirection of trac movement, but could also be used for controlling asignal for the opposite direction of traffic movement.

InA the drawing, four contacts are shown operated by each of the levers2V and 5V. Adjacent the symbol for each of the contacts of the signallevers V, a reference character is placed to indicate the position orpositions of the associated lever at which each of these contacts isclosed. For example, the letter N adjacent Contact of lever 2V meansthat contact 23 is closed when lever ZV'is in its N position only;letter R adjacent contact 28 of lever 2V means that contact 28 is closedonly when the lever is in its reverse position R; the letter D adjacentcontact 34 of lever 2V means that contact 3d is closed only when lever2V is in the D position; and the letters NL adjacent contact i3 of lever2V mean that Contact I3 of lever 2V is closed when lever 2V is in the Nposition or the L position or at any point between these two positions.

Each of the signal levers 2V and iV can be returned to its N positionfrom either its L or its R position only when an associated electriclock Winding is energized. Each of these electric lock windings isdesignated by the reference character M withra prefix corresponding Ytothat of its lever. Each electric lock winding M controls a locking dogI0 which, in turn, controls movements of a locking segment II which isprovided with a lug I'2.

Each' segment II is mechanically connected with its lever V, asindicated in the drawing by a dash line. One manner of connecting eachsegment I I with its lever V is such thatwhen the associated lever V ismoved to the left, the segment II will be moved to the right, or if thelever V is moved to the right, the segment Ii Will be moved to the left.When signal lever 2V or 4V is mo-ved to its reverse position R or L,respectively, the electric lock winding M for the associated lever willbe deenergized, and hence the dog I0 controlled by that winding M willrest on the corresponding segment II, and when an attempt is made toreturn the lever to its N position, dog I0 will engage the correspondinglug I2 when the lever reaches its position D or B, respectively, andwill thus prevent complete return of the lever to the Nposition untilthe associated Winding M is again energized. n

Because, in the drawing, lever 2V is shown controlling only an eastboundsignal, its electric lock winding 2M is energized by each of its threecontrol circuits shown only when lever 2V is in its lock position D.Similarly, lever 4V is shown controlling only a west bound signal, andhence its electric lock winding 4M is energized by each of its threecontrol circuits shown only when lever 4V is in its lock position B.

Switches 3 and 3a are operated by mechanismsV 3W and 3AW, respectively.These mechanisms are controlled in multiple by an electrical circuitwhich includes contacts 23 and 24 of levers 2V and 4V, respectively, andpole changing contacts 22 and 25 of a manually operable switch controllever 3V. Lever 3V, as shown, has only a normal position N to the left,and Va reverse position R to the right, corresponding to the normal andreverse positions, respectively, of switches 3 and 3a.

The primary windings of transformers 1, the local windings 9 of relaysZTSR, I'ITSR, 2RATR and 4LATR, the electric lock windings M of levers 2Vand 4V, the signal control relays 2RHR and LHR, power-01T relay POSR,signal lamps Y and R, and switch mechanisms 3W and 3AW are all energizedby current from a singleV source of power, not shown in the drawing buthaving terminals BX and CX. This source may, for example, be somesuitableV source of alternating current.

The contacts operated by the various relays and sign-al levers areidentified by numbers, each such number having a distinguishing prexfrom which it is separated by a dash when the contacts are shown apartfrom the relays by which they are operated. The prefix for each of thesecontact numbers comprises the reference character for the rel-ay bywhich it is operated. YFor eX- ample, contact 2RHR-30 in the circuitsfor electric lock winding 2M is identiiied'by the number 30 separated bya dash from the prex ZRHR. which is'the reference character for relay2RHR by which this contact is operated.

Having described in general the arrangement and control of the variousparts of one form of apparatus embodying my invention, I shall nowdescribe in detail the operation of the apparatus.

' As sho-wn in the drawing, all parts of the apparatus are in the normalcondition, that is, the various track sections are unoccupied and hencethe track relays R and SR are energized; switch and signal controllevers V are in the normal or N position, and hence the normal controlcircuit for mechanisms 3W and 3AW is closed and track switches 3 and 3aare in the normal position; power-off relay POSR is energized; signalcontrol relays ZRHR and ILI-IR and electric lock windings 2M and 4M aredeenergized; and red lamp R of each signal is lighted.

As shown in the drawing, the primary windings of transformers 'I'and thelocal windings 9 of relays ZRATR and IILATR are constantly connectedwith terminals BX and CX.

Both a pick-up circuit and the stick circuit are closed for relay ZTSR.VThe pick-up .circuit which is closed passes from terminal BX, throughcontact I3 of lever 2V, and winding 3 of relay ZTSRy to terminal CX. Thestick vcircuit passes from terminal BX, through contact I5 of relayZTSR,

and winding 9 of relay ZTSR to terminal CX.V

of relay 4TsR, and winding s of relay 4'rsR to' terminal CX. The pick-upand stick circuits are also closed for relax/ POSR. The pick-up circuitfor this relay passes from termin-al BX, through contacts I9 and 20 ofrelays ZTSR and 4TSR, respectively, and the winding of Yrelay POSR toterminal CX. The stick circuit Yfor this relay passes from terminal BX,through contact ZI of relay POSR, and the winding of relay POSR toterminal CX.

The normal energizing circuit for mechanisms 3W and 3AW, now closed,passes from terminal BX, through contact 22 of lever 3V closed in theleft-hand or N position, contact 23 of lever 2V closed in the Nposition, mechanisms 3W and 3AW in multiple, contact 24 of lever 4Vclosed in the N position, and contact 25 of lever 3V closed in theleft-hand or N position, to terminal CX.

The circuit by which red lamp R of signal 2R is lighted passes fromterminal BX, through the back point of contact 26 of relay ZRHR, and

red lamp R of signal 2R to terminal CX. A similar circuit is closed forred lamp R of signal 4L winding of relay 2RHR to terminal CX. Relay`ZRHR will therefore now open the circuit for red lamp R at the backpoint of its contact 26 and, at the front point of its contact 26, willclose the circuit for lamp Y of signal 2R, passing from terminal BX,through the front point of contact 26', and lamp Y of signal 2R toterminal CX.

If the leverm-an should now desire to return A lever 2V to its normalYposition before a train arrives on section ZRAT, he will move lever 2Vas far as the D position, thus opening at contact 28 the circuitpreviously traced for relay ZRHR. With relay 2RHR deenergized, a circuitwill now be complete for energizing magnet 2M of lever 2V,

passing from terminal BX, through contacts 2RHR-30 and 2RATR3L contact34 of lever 2V, and winding 2M to terminal CX. With winding 2Menergized, dog Ill will be raised out of engagement with lug l2,permitting the leverman to complete the return of lever 2V to the Nposition.

I shall now assume that the leverman again clears signal 2R as before,that a train arrives on section ZRAT, and that the leverman then decidesto return lever 2V to the normal position. As before, he will returnlever 2V as far as the D position, in which dog IS will engage lug I2and prevent further movement of lever 2V toward the N position. Withyrelay ZRATR now deenergized on account of the train occupying sectionZRAT, the circuit previously traced fcr magnet 2M will be open atcontact 2RATRf-3Ig @The leverman will therefore complete a secondcircuit by operation ci a time element device 2TE which, upon the lapseof a measured period of time, closes its contact, completing the secondcircuit, passing from terminal BX, through contact ZEER-3B, contact oftime element device contact 34 of lever 2V, and electric lock winding 2Mto terminal CX.

I shall next assume that the leverman, as before, clears signal 2R, andthat a train then enters section ZRA'I" and passes signal 2R intosection 2T. I shall further assume that while the train is in section2T, the leverman returns lever 2V toward the N position. With the trainoccupying section 2T, relay ZTSR will now be deenergized, and hence a.third circuit will be completed for winding 2M as soon as the leverreaches the D position, this circuit passing from terminal. BX, throughcontacts ZRHR-BD, 2TSR-32, and POSR-33, contact 34 of lever 2V, andwinding 2M to terminal CX. rIhe movement or lever 2V will therefore beinterrupted the D position only long enough for winding 2M to lift dogHl out oi engagement with lug l2. The leverman can then complete thereturn of ever 2V tol the N position.

I shall now assume that the leverman clears signal 2R, as before, andthat a train again enters section ZRAI, and that while the train occupessection ZRAT the source of power fails, and hence all parts of theapparatus are de energized. I shall further assume that while the poweris off, the leverman returns lever 2V as far as the D position. If nowthe source of power is restored, relays ZRATR, and QLATR will beenergized immediately. Relaiy POS'R being now deenergized on account oftrack relays ZTSR and 4TSR having been deenergized, a second pick-upcircuit is completed for winding 9 of relay 2TSR, passing from terminalBX, through contact POSE-I4, and winding 9 of relay TSR to terminal CX.A second pick-up circuit will also be completed for relay ZITSR, passingfrom terminal BX, through contact Il of relay POSR, and winding 9 ofrelay TSR to terminal CX. With relays ZTSR and lTSR thus energized, thepick-up circuit previously traced will again be completed for relayPOSR, which will then again complete its own stick circuit previouslytraced. With the train still occupying section 2RAI, the circuit rsttraced for winding 2M will bey open at contact ERA'IPf-Sl, and withrelay 2TSR. now energized, the third circuit traced for winding 2M willbe open at contact HSR-32, and hence the ieverman will again completethe circuit traced through the contact of time element device 2TE.

It follows that, on account of contact POSR33 being included in thethird circuit traced for winding 2M, winding 2M will not becomeenergized immediately, when the power source is restored, on account ofrelay ZTSR being at that time deenergized, and thus causing possibly anunsafe condition.

I shall next assume that the leverman again clears signal 2R', and thata train again enters section ZRAT, and that the source of power alsoagain fails. I shall further assume that the leverman does not changethe position of lever 2V, and that the power then again comes on. Withlever 2V still .in the R position, the circuit previously traced forrelay ZRHR will be closed as soon as relay Z'I'SR becomes energized whenthe power comes on, causing relay 2RHR, to be energized and signal 2R tobe cleared without further delay.

From the foregoing description and the accompanying drawing, it followsthat, with apparatus embodying my invention, if the power goes off of aninterlocking system for a brief period when a train is occupying theapproach section to the rear of a signal, the approach locking meanscannot be energized falsely on account of the detector track sectionrelay being deenergized, when the power is restored. Also, withapparatus embodying my invention, if the power fails in an interlockingsystem while a train occupies an approach section to the rear of asignal while the signal is clear, the signal will again clear as soon aspower is restored, without any action by the leverman if he has left thesignal lever in the reverse position.

Although I have herein shown and described only one form of apparatusembodying my invention, it is understood that various changes andmodifications may be made therein within the scope of the appendedclaims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination, a plurality of railway tracks divided into aplurality of track sections, a track circuit including a track relay foreach of said sections, a plurality of track switches in said sectionsinterconnecting said tracks, locking means when deenergized preventingoperation of said switches, a power-off relay, a common source ofelectrical current for energizing said track circuits and said lockingmeans and also said power-off relay, a pick-up circuit for said poweroirelay controlled by a front contact of each of said track relays, astick circuit for said power-01T relay for retaining said power-offrelay in the picked up condition at all times except when said source ofcurrent fails, and means controlled by said power-off relay in thepicked up condition and by back contacts of said track relays for attimes energizing said locking means.

2. In combination, a stretch of railway track including a track switch,traiiic responsive means, a power-01T relay, locking means which in thedeenergized condition prevents operation of said switch, a single sourceof electrical current for energizing said traiiic responsive means andsaid power-off relay as well as said locking means, means controlled bytraiic conditions on said stretch for energizing said traffic responsivemeans when said stretch of track is unoccupied lofy and for deenergizingsaid traffic responsive means whensaid stretch of track becomesoccupied,

means controlled by said traiic responsivemeansV inthe energizedAcondition for energizing said power-off relay, meansiortheneretainingsaid 5,E power-off relay in the energized condition until said source ofYcurrent fails, and` means controlled by said fpower-oi relay in theenergized condition and by said traffic responsive Ymeans in theVdeenergized condition vfor;v energizing said Y Vlgilocrking means.

circuit for saidpower-off relay controlledA by a-` 20 front contact Vofsaid track relay, .a stickv circuit "for Said power-oi'relay controlledonly by a front contact ofY said power-ofrelay, anda circuit controlledAby a'frontcontact of said poweroff relay'and by a back contact of saidtrack '25*relay for energizing said-lockingmeans. r y

4. In combination,a section of railway track includinga switchgatwo-element track relay comprising a track element Aanda local element,

a track-circuit. for said section including said 30 track element, apower-oir relay, a signal for governing traiiic -movementsY into saidvsection, a manual control device having a normal and a reverseYposition, locking-means which when deenergized prevents return of saidmanual control 35,'device to the normal position, a common source forsupplying electrical current for energizing said track circuit and theenergizing circuits for said power-off relay as well as said lockingmeans,

a iirst and a second pick-up circuit for the local 40, element of saidtrack relay controlled Yby said manual control 4device in the normalposition and by a back contact of said power-01T relay respectively, astick circuit for the local element of said track relay controlled byonly a front con- 145 tact of said track relay, a pick-up and a stickcircuit for said power-off relay controlled by a front contact of saidtrack relay and by a front contact of said power-off relay respectively,a circuit for energizing saidlocking means controlled by a dirontcontact of' said power-off Arelay in series with a back .contactof ksaidtrackrelay, VmeansY controlled by said manual control device inthereverse positionfor clearing. said signaLand meansffor operating saidswitch from one of vits extreme positions tothe other only ifsaidmanuallV controldevice. is in the normal position.

- 5. vIn combination, a stretch of railway track,j Va power-off relay, asignal for governing traiiic movements into said stretch, a manualcontrol device having anormal and a reverse position, a track relaycontrolled by trafc conditions in said stretch and having a rst and asecond pick-up circuit controlled by said manual control device in thenormal position and by a back contact of said power-off relayrespectively,-a stick circuit for said track relaycontrolled by a frontVcontact ofy said track relay, aY pick-up circuit for said power-offrelay controlled by a fro-nt contact of said track relay, a stickcircuit for said poweroff relay controlled by` onlya front contactofsaid power-Gif relay, a common source for supplying electrical currentfor energizing the pick-up and stick circuits for said track relay andsaid power-01T relay, and means controlled by said manual con-trol meansin the reverse position and by a front contact of said track relay forclearing relay, a manual-control device having a normal and a reverseposition, means controlled by saidV manual control device in the reverseposition. for

clearing said signal, locking means'which when it is deenergizedprevents return of said manual control device to the normal position, apick-up and a stick circuit for saidv power-off relaycontrolled by frontcontacts of said' track relay 'and said power-off relay respectively, acircuit kcontrolled by a front contact yof said power-oirrelay and by aback contact of said track relay forl energizing said locking means, acommon source of electrical current for energizing said track circuitand the energizing circuits for said power-off relayV and said lockingmeans, and meansrcontrolled in part by said manual control device in.

the normal position for operating said switch between its extremepositions. k

Y lCHARLES H. LAY.

